Acoustic device



Jan. 29, 1929.

G. R. LUM

ACOUSTIC DEVICE Filed Oct. 26. 1-922 Patentecl Jan. 29, 1929.

UNITED STATES PATENT OFFICE.

GEORGE LUM, 01' NEW YORK, N. Y., ASSIGNOB T WESTERN ELECTRIC COMPANY,INCORPORATED, OF NEW YORK, N. 'Y., A CORPORATION 01' NEW YORK.

I aoousrrc DEVICE.

I Application filed October 26, 1922. Serial No. 596,832. g

This invention relates to acoustic devices and particularly to portableloud speaking receivers.

The object is to provide a-unitary type 5 of loud speaking receiverwhich is cheap to manufacture and capable of delivering a large volumeof sound without noticeable distortion.

The resent invention provides a combination horn and stand for a loudspeaking telephone receiver. The horn has a tortuous shaped openinggiving the effect of a much larger horn and the base which is integraltherewith is hollow providing space in which the amplifying apparatusmay be mounted.

In the drawing, Fig. 1, is a cross-sectional view on line 1--1 of areceiver embodying the invention. i

Fig. 2 is a rear view broken on line 22.

The receiver consists of a body portion 6, the horn proper, anda hollowbase? integral therewith for supporting it. Within the base is mounted atranslating device or receiver unit 4. Both the. body and base portionsare preferably made of fibrous material and continuous. The horn mayconveniently be made in two symmetrical sections and cemented together,or otherwise joined along the line 1-1. The air path of the horn issinuous throughout its length and increases at the same rate asanconical horn having a straight airassage of the same length. The axesof a l'sinuous sections of the opening lie preferably in the same plane.Attached to the smaller end of the horn and within the base is athreaded ferrule 8 serving to support the receiver unit 4 which isprovided with a threaded flange 11 for engagement therewith. In 40 caseswhere it is desired to include a transformer 5, this may be convenientlydone by securing it to the receiver unit 4 in any wellknown manner. Abase plate 9 of any suitable material such as cardboard or fibre isattached to -the periphery of the base by cement or any other suitablemeans. This I. base late may be covered by suitable shock absor ingmaterial 10 such as felt,

The invention claimed is:

A sound amplifying device com rising a horn of fibrous material having abell portion, a hollow base portion integral therewith, said base beingin the form of a hollow outwardly flared portion to provide a chamherfor the reception of a receiver unit, a sinuous passagev leading fromthe base to the bell portion, said passage being composed of contiguoussinuous sections lying one above the other in the same vertical plane, amemher attached to the smaller end of the horn within the base forsupporting said unit, and plates of shock-absorbing material secured tothe large end of the flared portion of the base. 66 In witness whereof,I have hereunto subscribed my name this 24th day of October A D., 1922.

GEORGE R. LUM.

